YES! I've been saying for a while that the entire Home Plate construct looks to me like remnants of a hot spring complex. Especially the way in which the layers within HP have been cemented and laid down -- it suggests (to me, anyway) deposition by mineral-rich water that has alternated back and forth from flowing to pooling.

I've known that several members of the Spirit team have favored the hot spring theory for some time. It's nice to see that they're hanging in there and finding evidence for their theory.

-the other Doug

--------------------

“The trouble ain't that there is too many fools, but that the lightning ain't distributed right.” -Mark Twain

This might be bigger than it seems. I wonder what the implications will be for the interpretation of orbiter TES data now that there is ground-truth for amorphous silica.Would the exploration of Columbia Hills have taken a different course if this discovery was made earlier ?

This might be bigger than it seems. I wonder what the implications will be for the interpretation of orbiter TES data now that there is ground-truth for amorphous silica.Would the exploration of Columbia Hills have taken a different course if this discovery was made earlier ?

Oh yes... they'd have dragged a wheel all the way from the top of Husband Hill to Home Plate

The silica finding's yet another convincing demonstration (as if all the other multi-coloured salt deposits weren't enough) of the usefulness of doing 'scuff' operations (as opposed to brushing/RAT) to see what's below the surface - *and* another example of the serendipity that only rovers can really deliver, IMHO. ("What do we want? Dozens more MERs! When do we want them? When budgetary constraints, DSN bandwidth and management resources permit!" )_chug!_( )

Actually, it's surprising that there is so little overlap between the rovers' discoveries. Other than olivine found by both rovers early into the mission, all other unusual materials or features were found by only one robot. Silica and salt are only in Gusev, blueberries are only in Meridiani. Volcanic bombs are in Gusev, festoons are in Meridiani. Layered bedrock is radically different, and even sand doesn't seem to be the same.This means that more MERs are likely to discover more unique features if they are sent to new places on Mars. And even if they find something similar to Gusev or Meridiani, that would be exciting too.MSL and Phoenix may be better equipped, but it's clear that it's not enough to cover unique places on Mars. MERs are proven, there are specialists with years of MER experience, and there is Mars-tested MER software.I understand that NASA is supposed to innovate non-stop, but for the sake of science, sending more MERs would be the right thing to do IMHO.

Actually, it's surprising that there is so little overlap between the rovers' discoveries. Other than olivine found by both rovers early into the mission, all other unusual materials or features were found by only one robot.

Maybe not. Hate to sound like a one-trick pony on this & other threads, but we're finally discovering that Mars is a lot more diverse than we thought, even if its environment pretty much ground to a halt in terms of types of changes other than dust storms a few By back.

Think that the similar appearances of the Viking & Pathfinder sites (plus, of course, our inability to go over the next hill & see what might be there on these missions) instilled a bit of a stereotypical outlook in many of us...it sure did in me. "Mars looks like this and the surface is composed of that"...is a vast overgeneralization just as it would be if said about the Earth.

More MERs and the infrastructure to support them? Hell, yes...I'd gladly decline my tax refunds for the next five years to get them there.

--------------------

A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.

All these results shows the absolute genius in sending the same robust design to multiple locations.

Imagine if we took the same rover design (OK, tinker with it a tad based on what we've learned) and send it to more diverse locations. As they say in real estate: it's all about location, location, location. Heck, drop 'em down into the much more risky landing ellipses, even if only one survives, it will give us yet another view of Mars.

I also gotta believe rovers would be cheaper by the dozen.

Can we crank them out assembly line style? (Model T Mars Rover?)

(And I'll second nprev's comment: I'll forgo tax returns for 5 years for more Mars rovers, and I'd actually kick in extra bonus bucks for a Titan mission.)

Multiple MER's is a subject that's been done to death here and elsewhere. The bottom line is that while MER has been fantastic, the number of sites you can land with this system is very very small and very very limited and it's a highly inefficient way of getting a very small payload onto the ground. Because of that, MER's heritage should be in systems, not the entire vehicle.

If MSL works - you've got many orders of magnitude more Mars that can be accessed, and then it does make some sense to think about reusing MSL or indeed just its decent stage to deliver payloads.

I understand the RTG makes a significant part of the MSL mission cost, and it cannot be "reused", obviously. My uninformed guess is that RTG is one of the reasons why there will be only one MSL.But you are right, it would be nice to reuse as much of MSL as possible if it succeeds.

As much as I am drooling over the thought of MSL on Mars, I sure would feel better if there were two of them. I think there is some merit in the multi-MER concept. They are dynamite little explorers that have proven themselves and their EDL concept, but I think you run into a problem budgeting the large crew needed to keep many of them operating and exploring efficiently.

Getting back on topic...

QUOTE (ngunn @ May 22 2007, 12:15 PM)

Are we to assume that this silica is in its anhydrous form or could it contain some water of crystallisation?

That's an interesting question. If this silica is truly amorphous or non-crystalline, there can't be any water of crystallization. Besides, I am not aware of any crystalline form of silica that holds water. But opal is an amorphous form of silica that does contain variable amounts of water.

I don't know how they know that this silica is non-crystalline. Which instrument tells them that, or how do they infer it? I would suspect that if this material was not anhydrous, that fact would be widely advertised as further proof of water once on Mars. I think the mini-TES can see water wherever it may be.

I understand the RTG makes a significant part of the MSL mission cost, and it cannot be "reused", obviously. My uninformed guess is that RTG is one of the reasons why there will be only one MSL.But you are right, it would be nice to reuse as much of MSL as possible if it succeeds.

Reuse is meant to be reuse of the design by making additional copies of the original including the RTG. A copy mission could cost some fraction of the original mission cost.

Wouldn't it just mean some relatively minor modifications to the EDL system to make MER capable of landing in many more places? A bigger chute, larger retro-rockets? - The solar-powered concept is literally proving better and better for every day the rovers keep chugging on and making new discoveries.

As I understand it the MER EDL system can't be scaled up much more. You can't even launch an exact replica of MER on a Delta-2 anyway because of the poor Mars oppositions of the near future. So, you will need an Atlas or a Delta-4 which is 2x more expensive and offers a lot more payload... ergo you have a complete new mission. But I think/hope we will see some big solar powered rovers dangling on a skycrane EDL system in the future!

IMAGE COPYRIGHT
Images posted on UnmannedSpaceflight.com may be copyrighted.
Do not reproduce without permission. Read
here for further information on space images and copyright.

OPINIONS AND MODERATION
Opinions expressed on UnmannedSpaceflight.com are those of the
individual posters and do not necessarily reflect the opinions
of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer
UnmannedSpaceflight.com moderation team is wholly independent
of The Planetary Society. The Planetary Society has no influence
over decisions made by the UnmannedSpaceflight.com moderators.

SUPPORT THE FORUM
Unmannedspaceflight.com is a project of the Planetary Society
and is funded by donations from visitors and members. Help keep
this forum up and running by contributing
here.